Conventionally, there has been known a mounting method of mounting chips on a substrate (e.g., JP 2009-130293 A). The mounting method in this document includes a substrate-placement process of placing the substrate on a surface of a stage of a die bonding apparatus, and a bonding process of bonding a chip on the substrate by applying heat from a side of the chip, in order to heat a bonding surface of the chip and a bonding surface of the substrate placed on the surface of the stage, while the bonding surface of the chip is brought into contact with the bonding surface of the substrate.
In the substrate-placement process, the substrate is placed on the surface of the stage in a state where a heat insulation layer is between the stage and a schedule region of the substrate, on which the chip is bonded. As an example of the chip, an LED chip is shown, in which electrodes (not shown) are respectively provided on both surfaces of the LED chip in a thickness direction thereof. The LED chip includes a chip-side-bonding electrode formed of AuSn, as an electrode on a reverse side (a side closer to the substrate) thereof. In addition, it is shown that the substrate is formed with a silicon wafer, as an example. The substrate is provided with die pads as substrate-side-bonding electrodes, in schedule regions of the substrate on which the respective chips are bonded (at placement positions). Each die pad has a stacking structure of a Ti film and an Au film formed on the Ti film, and a portion of each die pad on the surface side is formed of Au.
In the bonding process, a prescribed step is performed, repeatedly depending on the number of LED chips to be mounted on the wafer. In the prescribed step, an LED chip is held by suction with a suction collet that is provided at a head of the die bonding apparatus, and is heated to a defined bonding temperature by a heater of the head through the suction collet. In this state, a bonding surface of the chip-side-bonding electrode is brought into contact with that of the corresponding substrate-side-bonding electrode, and then appropriate pressure is kept applied to the LED chip during a defined time period from the head side, and thereby the chip-side-bonding electrode and the substrate-side-bonding electrode are subjected to eutectic bonding. The defined bonding temperature is set higher than, for example, a melting temperature of AuSn that is material for the chip-side-bonding electrode. The appropriate pressure is set to be in, for example, a range of 2 kg/cm2 to 50 kg/cm2. The defined time period is set to about 10 scc for example.
Here, it is expected that the mounting method in the above document is required to recognize the chip with high accuracy through a recognition device of the die bonding apparatus, before the chip is held by the suction of the suction collet. In addition, it is expected that the mounting method in the above document is required to recognize a corresponding schedule region of the substrate on the surface of the stage with high accuracy through the recognition device, for aligning the chip on the substrate, before the bonding surface of the chip-side-bonding electrode is brought into contact with that of the corresponding substrate-side-bonding electrode. Therefore, for the above mounting method, it is hard to shorten tact time to be required for a mounting process in a production line, and improve throughput in the mounting process. Note that, the recognition device is generally constituted by a camera, an image processing unit and a monitor.